280 THK ICK A(JK IN CANADA. 



some living species of less boreal forms, not found in the 

 rieistocene beds. 



Some of tlie species, it will be seer, are of very wide 

 distribution in tbe modern seas, occurving in the raeific 

 as veil as in the Atlantic. 



As might have been anticipated from the relations of 

 the modern marine fauna, the species of the Canadian 

 Pleistocene are in great part identical with those of the 

 Greenland seas and of Scandinavia, where, however, there 

 are many species not found in our Vleistocene. The 

 Pleistocene fauna of Canada is still more closely allied to 

 that of the deposits of similar age in Britain and in 

 Norway. Change of climate, as I have shown in previous 

 pages, has been much more extensive on the east than 

 on the west side of the Atlantic, owing to the distribution 

 of warm and cold currents, resulting from the dill'ering 

 elevation of the land. 



It cannot be assumed that the fauna of the older part 

 of the Canadian I'leistocene is different to any great 

 extent from that of the more modern part. Such 

 difference as exists seems to depend on variations of 

 depth or on a gradual amelioration of climate. The 

 shells of the lower boulder-clay, and oi those more inland 

 and elevated portions of the beds wiiich may be regarded 

 as older than those of the lower terraces near the coast, 

 are undoubtedly more arctic in character. In some 

 localities they are confined to a few species such as occur 

 in the permanently ice-laden seas ol* Spitzbergen. The 

 amelioration of the climate seems to have kept pace with 

 the gradual elevation of the land, which threw the cold 

 ice-bearing arctic currents from its surface, and exposed 

 a larger area to the direct action of solar heat, and also 

 probably determined the flow of the waters of the (Julf 



